1. Field
Embodiments of the present invention generally relate to a magnetic read head for use in a hard disk drive.
2. Description of the Related Art
The heart of a computer is a magnetic disk drive which typically includes a rotating magnetic disk, a slider that has read and write heads, a suspension arm above the rotating disk and an actuator arm that swings the suspension arm to place the read and/or write heads over selected circular tracks on the rotating disk. The suspension arm biases the slider into contact with the surface of the disk when the disk is not rotating but, when the disk rotates, air is swirled by the rotating disk adjacent an air bearing surface (ABS) of the slider causing the slider to ride on an air bearing a slight distance from the surface of the rotating disk. When the slider rides on the air bearing, the write and read heads are employed for writing magnetic impressions to and reading magnetic signal fields from the rotating disk. The read and write heads are connected to processing circuitry that operates according to a computer program to implement the writing and reading functions.
The read head typically utilizes a spin valve-type magnetoresistive (MR) sensor, which has an antiferromagnetic layer, a pinned layer, an interlayer, and a free layer disposed between two magnetic shields. In order for the MR sensor to function correctly, the magnetization of the pinned layer may be pinned in one direction. The pinning of the magnetization direction of the pinned layer is achieved by unidirectional anisotropy induced from the antiferromagnetic layer.
Therefore, there is a need in the art for an improved MR sensor having high unidirectional anisotropy.